As the commercial significance of the Internet increases, business-to-consumer (“B2C”), business-to-business (“B2B”), and other electronic trading networks have become increasingly more prevalent. Each electronic trading network typically involves a set of users or trading partners (such as, for example, individuals, organizations, businesses, or e-marketplaces) that communicate among themselves in order to complete business transactions. In a typical electronic trading network, business transactions are restricted to users or trading partners who are subscribed to that network. If a particular user wishes to perform business transactions with users subscribed to different trading networks, the user must typically subscribe to and maintain log-in information for each of those trading networks.